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<DIV><FONT face=Arial size=2>I'm getting random and sometimes frequent/sometimes
infrequent cases where myth is recording audio pops. These occur with
my recording with the backend and the frontend idle. What has stumped
me is that I have many recordings now that are perfect, and some where there is
much popping present, and this is after I have been investigating and tweaking
based on recommendations from the archives. The last two recordings I
tried had one almost perfect, and the other with so many pops in a 30min period
I would have called it a static; I was using RTJPEG at 480x480 and the top shows
<30% system load and I don't see any load spikes. Based on this I don't
think its an issue of my cpu horsepower so I've been trying a lot of things to
fix it. When I listen to the line in from the tuner the audio sounds
perfect. Also these cases are with channels with a good incoming video
quality. </FONT></DIV>
<DIV><FONT face=Arial size=2> </FONT></DIV>
<DIV><FONT face=Arial size=2>So I'm stumped and need some advice.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Here's the setup and some options I've
tried:</FONT></DIV>
<DIV><FONT face=Arial size=2>1.8GHz pentium4, 1/2 gig ram, SoundBlaster Live!
(not 5.1), AverTV stereo with audio pass through to Live line in, Redhat 9, ALSA
.95 (also tried .94), mythtv 0.10, running both backend and frontend on the same
system.</FONT></DIV>
<DIV><FONT face=Arial size=2>yes DMA is on. and this is with a
single 120G drive with an 8MB buffer.</FONT></DIV>
<DIV><FONT face=Arial size=2>the vid card is a GF2MX running the nvidia driver
and it's working aok. the card output is at 800x600</FONT></DIV>
<DIV><FONT face=Arial size=2>I've reniced the frontend -10 and backend
-15</FONT></DIV>
<DIV><FONT face=Arial size=2>I've killed or removed all
non-essential services.</FONT></DIV>
<DIV><FONT face=Arial size=2>I've been using KDE, but I've tried TVWM and Gnome
with the same jitter, jerky, pop occurring randomly.</FONT></DIV>
<DIV><FONT face=Arial size=2>I've optimized the redhat kernel for the
p4</FONT></DIV>
<DIV><FONT face=Arial size=2>I added noatime to my /etc/fstab for the two hard
drive partions</FONT></DIV>
<DIV><FONT face=Arial size=2>I forced the SBLive IRQ to be on 7 and it's not a
shared IRQ</FONT></DIV>
<DIV><FONT face=Arial size=2>I've tried a few optimizations with myth so far,
including some where I've added extra statements in for the libs to include
-march=pentium4 (and tried w/ and w/out sse flags)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>As far a settings, I'm using</FONT></DIV>
<DIV><FONT face=Arial size=2>mp3 recording, 44.1kHz. no change with
uncompressed</FONT></DIV>
<DIV><FONT face=Arial size=2>and 480x480 mpeg4 and rtjpeg.</FONT></DIV>
<DIV><FONT face=Arial size=2>on average with mpeg4 recording the load average is
about 0.8-1 and it's pushing the cpu. I see video jerks some times, but most
audio pops aren't associated with video jerkiness. </FONT></DIV>
<DIV><FONT face=Arial size=2>on average with rtjpeg is well under half load and
I don't see any load spikes (noted really good/bad cases above).
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>If I had to guess, this looks like a lack of audio
buffering in myth, but since I haven't seen anything in the archive, and no myth
errors I've been trying different options.</FONT></DIV>
<DIV><FONT face=Arial size=2>rgds</FONT></DIV>
<DIV><FONT face=Arial size=2>Brent</FONT></DIV>
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